Apparatus for effecting gunnery calculations



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Y. P. G. LE PRIEUR APPARATUS FOR EFF'ECTING GUNNERY cALcULATIoNs allowance 2 Course of Me flrfny sse/ Feb, 24. 1925.

Y. P. G. LE PRlEUR APPARATUS FOR EFFECTING GUNNERY CALCULATIOHS 2 Sheets-shew?. 2

Filed tAug. 31. 1922 Patented Feb. 24, 1925.

UNITED STATES PATENT OFFICE.

'YVES PAUL GASTON LE PRIEUR, OF PARIS, FRANCE, ASSIGNOR TO SOCIT ANONYME LA PRECISION MODERNE, OF PARIS, FRANCE.

APPARATUS FOR EFFEC'IING GUNNERY CALCULATIONS.

Application filed August 31, 1922. Serial No. 585,569.

To all 'who-m t may concern.'

Be it known that I, Yms PAUL GASTON Ln PRIEUR, citizen of the French Republic, residing at G1 Rue` Pernety, Paris, France, have invented certain new and useful Ap para-tus for Effecting Gunnery Calculations, of which the following is a specification.

The problem of gun laying on board a vessel consists in furnishing to the pieces of artillery the elevation and the lateral allowance at each instant, these being essentially variable, which are required in order to place the projectiles upon the target. The values of the same will depend upon the following factors; the course and speed of the firing vessel, the course and speed of the target vessel, and the direction and force of the wind. The effect of these factors will be distributed upon the elevation and the lateral allowance according to the bearing of the target with reference to the firer i. e., the angle of the target counting from the front of the tirer. For determining these factors, account is to be taken of certain corrections, especially the drift of the pro'- jectile due to the riing of th-e gun.

Considering the firing plane, as defined by the firer and the target, the components according to this plan ofthe forces due to the said elements will give rise to corrections in the range, according to which the gun should be set in elevation, said corrections depending upon the distance and being furnished by the firing tables; these corrections are to be algebraically added to form the total correction which is added to the actual distance from the firer to the target which will give the modified range which is to be employed when elevating the gun. In like manner, the components, perpendicular to the firing plane, of the forces due to the said factors will have an effect upon the lateral allowance. By algebraically adding the resulting corrections and also adding the drift proper of the projectile, the total lateral allowance to be employed will be obtained. N,

As a rule, the firing officer measur estimates the value of the above-mentioned factors and then determines the desired co rections for elevation and lateral allowancel by the aid of the firing tables; he also adds,y

target in order to obtain the modified range, then adds the corrections for the lateral allowance and adds to the same the drift whereby he will obtain the total lateral allowance. But the use of the firing tables is a source of frequent errors and especially requires a certain time, so that instructions for the modified range and lateral allowance, which vary rapidly in some cases, will be subject to delay when communicated to the pieces.

When the firing hasv been commenced with the modified range and lateral allowance as thus found, an observation of the points of fall of the projectiles with reference to the target will often bring out errors for whose correction the firing oicer is led to make adjustments in the modified range and lateral allowance whereof he determines the value in each case.

The modified range and the lateral allowance, and especially the former, are subject to continual variations. Known devices are employed for automatically following the variations of modified range when one has determined the speed of approach of the firer and target and when one regulates or operates said devices in consequence. But said devices are not absolutely exact, as they occasion loss of time or fail to take account in an absolutely continuous manner of the rapid variations in the ring factors.

The present invention relates to a device which obviates all these drawbacks and shows in an automatic and instantaneous manner upon suitable dials the modified range and the lateral allowance to be used, after having set upon various other dials the estimated or measured values of the factors affecting the firing, i. e., course and speed of the firer, course and speed of the target and force and direction of the wind. The said apparatus also provides for making adjustments in modified range and lateral allowance when required.

The principle of the said apparatus is as follows: Three dials mounted on a common centre line are each provided with a graduated pointer which carries a cursor or slide;

said dials correspond to the firing vessel, the wind and the target vessel. The arms are oriented and the slides are placed so the setting of the cursors or slides relatively to the pointers can be provided in any known way, by example each pointer will carry a threaded rod and the cursor or slide, which is internally threaded, Will be displaced on the said rod along a graduation carried by the pointer.

The pointers are oriented to correspond with the direction of the speed of the iirer, of the speed of the wind and of the speed of the target, and the cursors are set upon said pointers in such a manner that the distances of said cursors from the axes of the pointers represent these speeds in magnitude but are of opposite sign to them.

The centre line represents the firing plane. The apparatus contains carriages which are actuated by the said cursors or slides certain of the said carriages being movable in a direction parallel and others perpendicular to the firing plane and these will show by their displacement the value of the components of these three speeds measured in the direction of the iiring plane and at right angles thereto. The displacements of said carriages, when combined with the action of cams which are formed in accordance with the firing tables and are turned or set according to the distance from tirer to target, will cause the movement of other carriages, whereof a certain number move parallel and others perpendicular to the firing plane, and will impart to said carriages various displacements which represent the corrections or modified range and lateral allowance which are due to each factor. The total sum of the components (according to the firing plane) of the speeds of the irer and of the target will give the speed of approach which is indicated upon a dial; a speed-indicator which is disposed on the same axis as the pointer of said dial is operated by hand so as to maintain coincidence between the pointer and that of the dial, i. e., so as to rotate at a speed corresponding to the speed of approach. The mechanism of said speedindicator also actuates one of the gear wheels of a double differential which carries the pointer indicating the modified range, and therefore if the latter indicates the proper modified range at any given m0- ment, it will continually follow the variations of distance due to the speed of approach. The totalizing (by mechanical means) of the corrections arising from the three components according to the firing plane will afford the total correction for the modified range, and this is transmitted to a second gear wheel of the double differential carrying the pointer indicating the modified range. Adjustments in the modified range will be made by acting upon another pinion of this double differential. In like manner the totalizing(by mechanical means) of the corrections for lateral allowance depending upon the three components perpendicular to the firing plane will be transmitted to one of the wheels of a differential whereupon is mounted the lateral allowance pointer. To this is added the drift of the projectile proper, by causing a cam formed by the use of the drift table and set according to the distance to act upon the second wheel of the differential. Adjustments in the lateral allowance are made by the angular displacement of the dial used with the lateral allowance needle.

A form of construction of the apparatus is set forth by way of example in the following description together with the accom.- p'anying drawings.

F ig. 1 is a general plan view of the top of the apparatus and of certain interior elements, and Fig. 2 a like view with the top cover removed showing the interior elements. Figs. 3 and 4 show on a larger scale the devices giving corrections for modified range and lateral allowance resulting from one of the said factors, speed of the tirer, of the wind and of the target. Fig. 5 shows on a larger scale and rotated through 90 the left hand part of Fig. 2, and adjacent the plan views are also shown various parts such as in Fig. 6 the speed-indicator and its mechanism in elevation; in Fig. 7 the double differential actuating the pointer for elevation value and its mechanism; in Fig. 8 a

diagrammatic section of the double differential; in Fig. 9 the differential actuating the lateral allowance pointer and its mechanism; and in Fig. 1() a diagrammatic section of said differential.

Along the central line 18 of the box 1, Fig. 1, are disposed three dials 2, 3, 4c corresponding respectively to the firing vessel, the wind and the target vessel.

The dials 2, 3, e are rotatably mounted respectively upon orienting dials 11, 12,13 which are connected together, as hereinafter explained, so as to be always oriented alike. Upon the dials 2, 3, 4 are rigidly mounted pointers 5, 6, 7 respectively, and along the said pointers may be respectively displaced cursors or slides 8, 9, 10; the pointers are oriented relative to the dials 11, 12, 13 and the cursors set in such a manner that the vector distances from the axes of the pointers to the cursors correspond in direction and magnitude according to the chosen scale, to the speed of the iirer, the absolute speed of the wind and the speed of the target, but are of opposite sign to them. The dials 11, 12, 13 are graduated in degrees and are marked to correspond with the points of the compass, north, south, east, west. These dials 11, 12, 13 are to be oriented in such a manner that the north to south line on the orienting dials occupies with reference to the central line 18, the same relative position as the actual north and south line occupies in space with reference to the actual plane of firing. For this object it is necessary to impart to the dials 11, 12, 13

.the orienting dials.

an angular displacement equal to the algebraic sum of the bearing of the target with reference to the firing vessel, and of the course of the firing vessel.

For this purpose a hand crank 14 placed beside the dial 2 of the firing vessel drives a gear wheel 15 mounted on shaft 16 which carries the worm gear engaging the dial of the firing vessel 2; said crank 14 Orients the pointer 5 representing the firing vessel so that this pointer 5 will make with the firing plane 18 represented by the centre line common to the three dials 2, 3, 4 an angle equal in magnitude but of opposite sign to the bearing of the target relative to the firing vessel. The gear wheel 15 is engaged with the gear wheel 19 of a differential 20 whereof the other wheel 21 is driven by a worm 22 mounted on a shaft 23 whereof the handle 24 is operated by hand according to the bearing of the firing vessel. The shaft 25 of the planetary gears of differential 20 carries three worm wheels 26, 27, 28 respectively engaging the orienting dials 11, 12, 13. The rotation of the shaft 25 is equal t0 half the algebraic sum of the rotations of the wheels 19 and 21, and consequently corresponds to the algebraic sum of the course of the firing vessel and of the bearing of the target relative to the firing vessel. This shaft 2 5 will thus correctly set the orienting dials 11, 12, 13 in the direction hereinbefore stated.

The setting of the wind pointer 6 on its dial 12 is effected by crank 29 actuating gear wheel 30 pertaining to a differential 31 whose other gear wheel 32 engages a wheel 33 keyed to the shaft of orientation 25 of i In this manner the shaft 34 of the planetary gears of the differential 31 (similar to differential 20) which is provided with a worm wheel 35 engaging the wind dial 3 will give to said dial and hence to wind pointer 6 secured thereto a correct orientation with respect to its orienting dial 12. In like manner the setting of the target pointer 7 on its orienting chal 13 is eected by crank 36 engaging a gear wheel 37 of a like differential 38 whereof the other gear wheel 39 engages a wheel 40 on the orientation shaft 25 of the horizon dials. 1n this manner, the shaft 41 of the planetary gea-rs of differential 38 provided with a driving worm 42 engaging the target dial 4 will place the target pointer 7 in the correct orientation with respect to its dial 13.

By means of said devices and the operation as indicated, the firing combination apparatus will afford a correct representation, with respect to the orienting dials, of the orientation and the speeds of the firer, the target and the wind, as well as of the firing plane.

The determination of the components of each of the speeds i. e., those of iirer, wind and target is eifected by devices of identical nature whereof only one need be described, for example the one used for the speed of the firer, said devices being shown in Figs. 2, 3 and 4.

Below the firing dial 2 and its orienting dial 11 is mounted a carriage forme-d by a plate 43 (Figs. 2 and 3) having the slot 44, perpendicular to the firing pla-ne, and which can only be moved parallel to the firing plane. Below said plate is a second carriage formed by a plate 45 (Figs. 2 and 4) having the slot 46 parallel to the firing plane, and which can only be moved perpendicular to the firing plane. As previously explained the cursor 8 is mounted upon the firing pointer 5 which has been properly oriented in such a manner as to make with the line 18 the same angle as the course of the firing vessel makes with the plane of firing. The cursor 8 is set at a distance from the axis of rotation of the pointer 5 representing on the chosen scale the magnitude of the speed of the lirer, but being of contrary sign thereto. The cursor 8 is provided with a vertical stud which is engaged both in slots 44 and 46. In this manner, the plates 43, 45 will at each instant have received-with reference to their zero position corresponding to the setting of the cursor 8 at the centre of its diala displacement according to the firing plane and perpendicular to said plane which will n'ieasure the components (according to these two directions) of the speed of the firing vessel.

To ascertain from the components of the speeds of the firer and of the target according to the plane of firing, the speed of approach of the two vessels, the following mechanism has been devised. The upper carriage of the iirer, Fig. 2, carries the pulley 47 and the corresponding carriage of the target carries the pulley 48; upioln said pulleys is mounted the. cable 49 having one end fixed at 50. Said pulleys have movements parallel to the firing plane which correspond to components (in this plane) of the speed of the iirer and the speed of the target, and therefore the outer end of the cable 49 will move by a quantity equal to the algebraic sum of these two components; said outer end is wound upon a drum 51, Fig. 6, which is secured to a pointer 54 moving on a dial 53 graduated in speed of approach. The speed of approach thus found will be used to vary the modified range in a continuous and corresponding manner by means of the following devices.

The dial 53 pertains to a speed-indicator whose pointer 52 is mounted on a copper bell 52 actuated at a distance by a magnet 53 mounted on a flywheel 53". The speedindicator is actuated by a shaft 55, Fig. 5, provided with a hand crank 56, by means of a loose gear wheel 57 adapted to be coupled to the shaft by a j aw clutch 5S controlled by the handle 58', Fig. 2, and rods 59, 597 said clutch being normally engaged. The shaft 55 ends in a worm 59 which is in gear with a wheel S4 which through suitable transmission operates the pointer 60. By example the wheel Se is tixed to a pinion 151. The pinion 151 is in gear with the pinion 152 lived upon the shaft 1h33 which carries also the ion 1,5%; wl with the pinion to which the pointer 60 lined. rihe pinion 60 indicates the hundreds ot metres ot the actual distance on the range dial Said dial is also provided with a pointer 02 ior kilometres of distance which is connected with the former by suitable gearing. The handle 5G is operated so as to maintain the pointer 52 ot the speed or in con orda. vcr-u the pewterl :1i and this will rotat, t e-indicator a Sl speed corresponding to this speed of approach. One will thus vary the indication lor the distance by amounts corresponding to said speed of approach. rElie apparatus is regulated so that the distance will vary on the dial. in a given time. by the amount of variation in the true distance between lrer and target.

Concerning the mechanism ttor totaliaing the corrections 'for modified range and the addition or" the same to distance. the modified range is given as Afollows. Fig. 3. Each ot the three carriages e?) (for instan *e that oit the tirer) carries a button engaging a slotted arm Gal pivote/l at a iixed point (55. Below said arm is the carriage 0G having a slot 0T perpendiculail to the tiring plane and movable only parallel to said plane; below said carriage is a second carriage GS, Fig. -1 which can move only perpendicular to the tiring plane and is provided with aguide parallel to the tiring plane wherein is movable a ilat bar G9 provided with a vertical stud engaged in the slot GT ot carriage GG and in the slot oi' the arm 6i. rflic position of the carriage GS in its movements perpendicular to the tiring plane is regulated by a cam 7l pivoted at 72 and actuating a roller 73 disposed on carriage GS. The cam 7l is secured to a worm wheel i2-3', Fig. 2, engaging a worm 74 mounted on a shaft 75 which is driven by the shatt (used tor the distances) through the medium ot a gear wheel T0 and a. worm 76 disposed on shal't The cam Tl is given an outline according to the tiring table which gives the correction for moditied range due to the component ot the speed et the tirer in the firing plane. Said correction cepends upon the actual distance and said component of speed. Cam 7l may be so formed that the value of the movements (parallel to the plane of tiring) out a pulley 77, Fig. 3, mounted on carriage 66, shall represent this correction at the chosen scale. In like mannei'. the corrections :for modified range due to the wind and to the target will be measured by the displacements of pulleys 7S, 79, Fig. 2. mounted on carriages analogous to chariot (36 and actuated in like manner. The totalization ot these three corrections is carried out by means of a cable whereotf one end secured at Sl and which is disposed upon the three pulleys 77, 78, 79, and whe;l .it the other end is wound upon the wheel ot a dili'erential S3 Fig. 7, whereo the other gear wheel is driven by the i 'for the distances and whose secondary shaft 8f3 8, carrying the to the lower gear The 4 is secured ot' a second di'lierential 83. adjustments tor modicd range can be obtained bj.' a crank 85 Fig. 2, driving a shalt S5 ending in av worin Sti which engages the el 80 of this second dilierential whereoi the secondary shaft ot the ary cfrries the pointer 60 iny the modilied range. The shaft S5 a tuates a pointer ST, Fig. Z7 moving on ral 88 whcreon are shown in the desired .ense the moflilied range adjustments produced, thus all'ording a. check upon the same.

The mechanism 'for totalizing the corrections tor the lateral allowance is as follows. For each ot the three dials7 that ot' the tirer, for example, the carriage 45, Fig. 2, is given (as stated) a displacement perpendicular to the firing plane which measures the component of the spoed of the tirer according to this direction. It is now proposed to bring this displacement parallel to the firing plane so as to obtain a certain symmetry in the apparatus concerning the three dials for firing7 wind and target in effecting to some extent a correspondence between the elements used r'or totalizing the corrections value and those used for totalizing the corrections .tor lateral allowance. To this end the carriage d5, Fig. l, is provided with a button 89 actuating the arm 90 oi a bell-crank lever pivoted at the fixed point 91 and whereotl the` other arm 92 is provided with a slot 93. Below said lever is a carriage 9a having slot 95 perpendicular to the tiring plane` and movable only parallel to the firing plane. Eelow said carriage 9d is disposed, Fig. 8, a second carriage 9G mora-ble only perpendicular to the tiring plane and provided with a guide 97 parallel to the firing plane wherein is slidable a flat bar 9S provided with a vertical stud 99 engaging both in the slot 95 ot carriage 94. and in the slot of the arm 92. The carriage 96 carries a roller 100 which is constantly pressed by a spring upon a. cam 101 pivoting on the axle 102. Said cam has a profile which is determined according to the table ot corrections :tor lateral allowance corresponding to the component` of the speed of the iirer perpendicular to the firing plane.

This correction depends upon the said component and the distance. The cam 101 may be so shaped and actuated that the movement of carriage 94 parallel to the firing plane will represent the said correct-ion on the chosen scale. Cain 101 is secured to a wheel 103, Fig. 2, actuated by a. worm 104 mounted on a shaft 105 driven from the distance shaft 55 by means of the gear wheel 106 and the worm 106 mounted on shaft 55. The carriage 94 carries a pulley 107; in like manner the pulleys 108, 109 are disposed upon carriages similar to 94 corresponding to the wind and to the target. A cable 110 whereof one end is secured at 111 is disposed on the three pulleys 107, 108, 109 and is wound at the end on one of the pinions 110 Fig. 9. of a differential 112 whose secondary shaft 113 carries the lateral allowance pointer 114 moving on the dial 115. The second gear wheel 116 of said differential is actuated by a rack 125 controlled by a cam 126 which is formed according to the table of corrections for drift of the projectile due to the rifling which depend upon the distance of the tirer from the target; cam 126 is secured to a worm wheel 12T actuated by the worm 104 on shaft 105. The dial 115 is actuated by the worm 117 mounted on a shaft 118 handcontrolled by the cra-nk 119, Fig. 2, and serving to obtain the adjustments in lateral allowance, these being shown with their sign (to the right or left) on a dial 120 whose pointer 121 is also actuated by the` shaft 118 by means of a worm 118.

It is necessary that the control shaft 55 for the dist-ance pointer shall be disengaged at will from the speed-indicator which it drives, so that the distance may be rapidly varied either at the commencement of the firing or upon changing the target, or again, in the event of a considerable error, and to this end the jaw clutch 58 of the loose driving wheel 57 can be disengaged by means of the handle 58.

In certain cases it may be advantageous to use as the. basis of the firing corrections not the true speed or true direction of the wind, but the apparent speed and direction of the wind with respect to the firing vessel. To Jfacilitate in this case the movement of the wind pointer 6, Fig. 1, there is disposed below the orienting dial thereof a second dial 122 having a checking arrow pointer 123 used for reproducing the bearing of the firing vessel and which is brought parallel thereto by means of gearing 124, 124 which is actuated by the firing dial 2 and drives the dial 122. After measuring the apparent speed and direction of the wind, it is simply necessary in order to orient the wind pointer 6 to operate the crank 29 so that the wind pointer 6 shall have a measured angle with the arrow pointer 123.,

The speed-indicator will only operate in a regular manner when the hand control of the same is neither too fast nor too slow. T he crank 56 is used for the high speeds of approach; for small speeds, use is made of another crank 56', Figs. 2 and 6, actuating the flywheel of the speed-counter by an endless belt 56 formed by an endless coiledY wire spring, the said drive having a speedincrease ratio which is smaller than the preceding and is adapted toislip, so that the flywheel of the speed-counter, which moves by its own inertia will have a more regular movement than if it were rigidly connected with its hand control means.

rllhe firing oliicer is required to have before him the distance from tirer to target, and the totals of the corrections for modified range and lateral allowance resulting from the three elements, firer, wind and target. As stated, the act-ual distance is shown by two pointers 60, 62 whereof one corresponds to hundreds of meters and the other to kilometers, this second pointer being controlled by the first by means of suitable gearing.

The tot-al of the three corrections for' moditied range is shown by a pointer 129, Fig. 2, actuated by the gear wheel or druin 82 upon which the three corrections are totalized.

The total of the three corrections for lateral allowance is shown by a pointer 130, Fig. 2, actuated through a suitable gearing (see Fig. 2) by the gear wheel or drum 110 upon which these three corrections are totalized. It must be remarked that the pointer 130 gives only the corrections arising from course of tirer, course of target and wind, and thatthe drift correct-ion is not added to the said three corrections, whereas same is comprised in total given by pointer 114.

What I claim is:

Apparatus for effecting gunnery calculav tions comprising three pivoted pointers,

whose axes are situated upon a common straight line, a cursor upon each pointer, means for orienting said pointers and for setting the said cursors in such a manner that the distances of the cursors from the axes of rotation of the pointers correspond in magnitude, but are of contrary sign to the vectors representing the speed of tirer, speed of wind and speed of a target, while the line of the axes corresponds to the firing plane; means for obtaining the components of said vectors in the direction of the firing plane and in a plane perpendicular to the same; a totalizing device for the components in the tiring plane of the speed of the tirer and speed of target, said device comprising a pointer indicating the speed of approach; a speed-indicator and means for actuating the same at the said speed of approach,

ries with the distance of the three correc-.

tions for modified range due to the components-parallel to the firing plane of the three speeds of tirer, wind and target; a totalizing device for these three corrections; a double differential carrying the pointer for the modified range and totalizing upon the same the movements which it receives from the means actuating the speedindicator, from the device for totalizing the three corrections for modified range and from the actuating shaft for effecting adjustments in the modified range; means for indicating the total value which varies with the distance of the three lateral allowance corrections due to the components perpendicular to thev firing plane of the threespeeds of tirer; wind and target; a differential carrying the pointer for lateral allowance and totalizing upon said pointer the movements which it receives from the device tot-alizing the three corrections for lateral allowance and from a camactuated by the means actuating the speed indica-tor and indicating the drift; and a device for YVES PAUL GASTON LE PRIEUR. 

